A video wall includes multiple visual display units, such as including one or more computer monitors, video projectors, or television sets. Some display technologies that can be used in a video wall include an LCD panel, an LED array, a DLP tile array, or a rear projection screen, among others. Visual display units in a video wall can be tiled contiguously or in an overlapping manner to provide a larger display area than would be otherwise available using only a single visual display unit. In some examples, different types of displays (e.g., computer monitors and video projectors) can be used together in a video wall or other video system installation.
Visual display units designed for use in a video wall can be substantially frameless or have narrow bezels to minimize gaps between active display areas. Some visual display units include hardware that can be used to couple or stack multiple units together, along with electrical or optical communication ports to receive power, video, or other data signals from a central controller.
A simple video wall can be controlled using a multi-monitor video card, such as from a personal computer. More complex video wall arrangements can use a dedicated video wall controller with one or more dedicated video processing circuits, such as can be designed primarily to manage large video walls. A video wall controller can receive image information and apportion the image information into multiple parts corresponding to one or more display units that are available for use in a video wall.
A hardware-based video wall controller can include an application-specific device that includes one or more video processing chipsets, and may not include a dedicated operating system. An advantage of using a hardware-based video wall controller can include improved reliability and performance over a software-based controller. However, such hardware-based controllers can be expensive and lack flexibility, and may therefore be impractical for atypical video wall applications, or for applications with display unit arrangements that change frequently. One example of a hardware-based video wall controller includes a single-input multiple-output scaler. The scaler can receive one video input signal and divide image information from the video input signal into multiple parts corresponding to different visual display units.
A software-based video wall controller can include a computer configured to operate software that controls multiple different graphic output devices, such as multiple different video cards in a personal computer system. An advantage of using a software-based video wall controller can include increased flexibility because a user can configure the software to work with a particular available video display unit and driver hardware arrangement. However, a disadvantage can be that implementation of a software-based video wall controller depends upon speed and reliability characteristics of the underlying computer system.
A video wall including multiple video display units can receive video information over an IP (internet protocol) network, sometimes called Video over IP. In Video over IP, a standard video codec can be used to reduce video program information to a bitstream (e.g., an MPEG transport stream including packetized data), and then an IP network can be used to carry the bitstream to a specified one of multiple video display units, such as using a Real-time Transport Protocol (RTP or RTTP). Video information exchanged using IP is time-critical and generally is prioritized in a Video over IP system (e.g., over non-time-critical configuration or other data exchanged over the network) to maintain a minimum quality of service.
A matrix switch can be used in video wall or other video-based systems. A matrix switch includes multiple inputs and outputs wherein any one of the inputs can be selectively connected to any one or more of the outputs. In some examples, a matrix switch can be used in audio, video, or other systems for routing signals to numerous output devices from one or more input devices, and can be controlled manually using one or more physical switches, or can be controlled automatically using a computer. Some matrix switches include internal, non-scalable backplanes that fix a number of inputs and outputs of the matrix switch. In other examples, an expandable matrix switching system can be used.